A circuit device for simulating a selected one of a plurality of process transducers, including: signal input and output terminals connectable to external conductors; a plurality of circuit components (90,92,94; 104,108) connectable between the signal input and output terminals; a coupling device (106) connected between two of the circuit components for conducting a signal between the two components; and selective connecting members including connector terminals connected to at least one of the circuit components (90,92,94; 104,108), and connector elements for establishing conductive connections between selected ones of the connector terminals for configuring the circuit device to apply to the signal output terminal a signal corresponding to the output signal of a selected transducer.